On Wednesday 07 October 2009 10:35:19 Peter Tyser wrote:
--- a/lib_generic/string.c +++ b/lib_generic/string.c @@ -449,7 +449,16 @@ char * bcopy(const char * src, char * dest, int count) void * memcpy(void * dest,const void *src,size_t count) { char *tmp = (char *) dest, *s = (char *) src;
u32 *d32 = (u32 *)dest, *s32 = (u32 *) src;
/* if both are aligned, use 32-bit copy */
if ( (((int)dest & 3) | ((int)src & 3) | (count & 3)) == 0 ) {
count /= 4;while (count--)*d32++ = *s32++;return dest;}
/* else, use 1-byte copy */ while (count--) *tmp++ = *s++;
If we're adding this logic, what about adding it such that:
if (src/dest are 32-bit aligned and count > 3) { perform 32-bit copies till count <= 3 } perform remaining 8-bit copies till count == 0
You'd still get the performance boost but not have the requirement that count is evenly divisible by 4. You could do byte copies before the 32-bit copies to align the src/dest in some cases, but that might be overkill...
i thought the same but didnt feel like sending out another e-mail ;) -mike